PTL 1 discloses cell broadcast service (CBS) in a 3G (Third Generation mobile communication) network. The CBS is a system, for example, that delivers a broadcast message (a CBS message) to all terminals (UE: User Equipment) existing in a particular area, such as a region where a seismic intensity is expected to be a predetermined value or more when an earthquake occurs.
As explained in PTL 1, a CBC (Cell Broadcast Center) that delivers a CBS message manages an area by a cell ID of each RNC (Radio Network Controller) in an existing 3G network. Therefore, when the CBC obtains an instruction to deliver a CBS message from a CBE (Cell Broadcast Entity) server of the Meteorological Agency or the like, the CBS message is delivered to an RNC by the cell ID appropriate to a delivery target area. Each RNC receiving such message delivers a CBS message to a UE under a BTS (Base Transceiver Station) and replies to the CBC that the delivery is successful. As above, the broadcast CBS message is delivered to each UE in the existing 3G network.
Also, a base station for a femto cell covering an extremely narrow range with a radius of about several tens of meters has been recently installed. The femto cell base station is mainly installed at home or at an office and covers an indoor communication area.
NPL 1 discloses a network configuration of the CBS, operation of each device with which the CBS is configured, and the like. NPL 2 specifies a protocol between a CBC and an RNC (HNB-GW: Home Node B-GateWay), that is a SABP (Service Area Broadcast Protocol). It is noted that a CBS message delivered from the CBC as urgent news is transmitted to a service area (SA) and one SA is defined as one cell according to NPL 2.